I want to create a POS coin and here:1. I use POW such as X11 to premine coins in genesis block and the 2nd block, then after block 3, I set the reward to 0 after block 3. 2. set LAST_POW_BLOCK=43. I also set the aanual rate etc for POS

This means, after block 4, the POW will stop? so after block 4,1. whether I still need to mine in order to keep sync?2.if somebody just leave the wallet open and NOT mine, whether the sync can still be kept?3. no cpu resource will be used after block 4, correct?Thanks